The total energy of an electron in the first excited state of the hydrogen atom is $-3.4 \ eV$. Find out its potential energy in this state.

The energy of a hydrogen atom in its ground state is $-13.6 \ eV$. The energy of the level corresponding to the quantum number $n = 2$ (first excited state) in the hydrogen atom is......$eV$.

$A$ hydrogen atom absorbs radiation of wavelength $975 \, \text{\AA}$ to transition from the ground state to an excited state. To which energy level will the atom transition?

The ratio of the energies of the electron in the hydrogen atom in the first and second excited states is

The ionization energy of hydrogen is $13.6 \text{ eV}$. The energy of the photon released when an electron jumps from the first excited state $(n=2)$ to the ground state of a hydrogen atom is (in $\text{ eV}$)